Hi Drift,
I own a FHSS, and I am facing this problem as well. I have asked another user, and he face the same problem. The reason is that the receiver take a longer while to bind with the transmitter compared to other brands.
The only way I can solve this problem, is to turn on your transmitter and the next few seconds turn on the receiver immediately, and the binding will work faster. This will help most of the time but not all the time, once in a while it will take a longer while to bind as well.
Hope this work for your case. Thats why I use the fail safe to prevent it from running off.